Individuals may love agelessness, but let's not kid ourselves that it's anything but a disaster for species, society, etc.
More concretely, evolutionary pressure for immortality is nil when reproduction (including evolution itself!) is a more efficient way to spread and preserve genetic material.
If anything, aging + death would be the evolved trait to ensure smoother adaptation!
Things might have more stability, but change and opportunity would hardly exist and each succeeding generation would be permanent underclasses of children.
"A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it. " - Max Planck
You're right, however to me what seems worse path to take evolutionarily is to choose to destroy accumulation of experiences and knowledge by not passing it to next generation and instead starting with the first rudimentary step of half DNA crossing combined with random mutation.
Though we have developed ways (books) to pass that knowledge to next generation in place of nature, experiences are still lost.
It seems like evolution is more focused on the survival than survival of the fittest.
If that stops being the case it will lead to more political action. And potentially more force. Not sure if that’s good or bad for society.
My assumption is historical learning is valuable up until some percentage of your memories are false and/or obsolete. Even in a perfectly healthy individual both happen continuously.
At some point an empty vessel has more utility than a trained up individual. So some heuristic that arbitrarily purges old people and their ideas is adaptive.